Industrial trucks, cranes and lifting tackle of the most varied types and with the most varied mounted implements are known for manipulating and transporting heavy objects. Generally they have a vertical guide structure or rail structure for a lifting fork or other manipulating means or load carriers, such as shovels, bars, pincer grippers, etc. For fork lift trucks there are also special mounted implements and these are available in many different forms and for many different purposes, so as to increase the number of possible manipulations. The sought possibilities are generally achieved with such mounted implements and due to the vast number of different uses and requirements for the individual manipulations, it is necessary to provide a corresponding, problem-adapted mounted implement. A fork lift truck equipped with a manipulator is always in the position to "grip" the object, e.g. a container to be manipulated and to bring it to the desired point, where it can be deposited or only emptied.
However, problems occur if the particular object not only has to perform translatory movements, but is also to be rotated and in this way brought into other spatial positions. For such purposes e.g. rotary means, turn-a-load pallet turning means and rotary gripping clips are known. However, these manipulators suffer from the disadvantage that the loads are essentially only rotated about an axis parallel to the direction of travel of the truck. Normally there are clips or claws arranged in such a way that the centre of gravity of the load to be rotated is located on the rotation axis or fulcrum. This concept leads to problems if, during the handling of heavy loads which e.g., as a result of the characteristics of their surface, cannot be held on the outside by means of clips, the centre of gravity of the load is located alongside the rotation axis. Due to the lever arm, it is then possible for considerable forces to occur, which render impossible an accurate and rapid manipulation and constitutes a severe load for the bearings and joints. Moreover conventional manipulators do not make it possible for heavy loads to bring an e.g. circular cylindrical body into at least three given main positions without moving the truck where, as is desired in many cases, the axes of the circular cylinder are perpendicular to one another. In order to be able to bring a three-dimensional body into three such main positions use is made in other technical fields of means with three rotation axes which are vertical to one another and which correspondingly permit three degrees of freedom. In the case of uses under the aforementioned limit conditions, particularly the considerable weight of the loads to be manipulated, the requirement of long levers for rotary and bending movements, such as are e.g. known in the case of gripping arms of handling equipment in robot technology, as well as the need for rotational degrees of freedom and correspondingly complicated arrangements, would appear to be an obstacle which is unavoidable in connection with the wish for three main positions of the load to be rotated. Thus, conventional manipulators on industrial trucks generally use constructions with two rotational degrees of freedom with two axes at right angles to one another and it is necessary to accept the frequent movement of the truck for carrying out the third degree of freedom and also the massive constructions as a result of the forces which occur.
Similar problems occur in connection with the manipulation or handling of loads by means of cranes. A crane can e.g. be fixed or positioned on rails, or in less frequent cases can also be freely movable. In the industrial field frequent use is made of cranes with carriages. Particularly when using fixed cranes and cranes with rails or a carriage, the problem of the spatial rotation of loads is exacerbated, because no rotational degree of freedom can be obtained through moving the crane. In addition, the carrying cable is unable to take up torques.
In many applications heavy objects must be "gripped" from frames or e.g. production machines using such manipulators and deposited in intermediate or final storage places. Thus, particularly in the printing industry, a large number of printing products are wound onto the roll hub, said rolls then being manipulated and stacked in groups. The necessary manipulations generally involve the raising or gripping of standing rolls, i.e. the axis thereof is horizontal and the subsequent stacking of lying rolls (axis vertical). They are generally stored at a special point, so that a corresponding transportation path is involved. This procedure normally requires a large number of movements backwards and forwards, so that the use of several vehicles is made more difficult, because the travelling paths of the individual vehicles generally cross and therefore real traffic problems can occur. In addition, the path/manipulation ratio in such operations is unfavourable, i.e. said work is more time and energy intensive than it should be. This problem can partly be reduced by organizational measures, but cannot be completely eliminated, because e.g. it is only possible to reduce the length of the path, but not the number of movements backwards or forwards. A subdivision of tasks between a manipulating means and a transportation means does not obviate the problem, because this would merely increase the traffic problem, because an additional means would have to be used.